code: def get_differential_var(d):
      text = get_differential_var_str(d.getText())
      return sympy.Symbol(text)
  
imports: from importlib.metadata import version
  import sympy
  from sympy.external import import_module
  from sympy.printing.str import StrPrinter
  from sympy.physics.quantum.state import Bra, Ket
  from .errors import LaTeXParsingError
label_desc: Use image node_id 23 for calling a global function with example usage: get_differential_var(d) and returns: sympy